Block for paving and the like and process for making the same



Patented Apr. 7, I925 STATES isaatat relic.

ATE?

MONROE LAWRENCE PATZIG, or nss MOINES, IOWA. I

BLOCK FOR PAV'ING AND THE LIKE AND PROCESS FOR- MAKING THE SAME.

1\T o Drawing.

' To all whom it may concern:

Be it known that I, MONROE LP TZIG a citizen of the United States, and a resident ofDes Moines, in the county of Polk and State of Iowa, have invented a. certain new and useful Block for Paving and the like and Process for Making the Same, of which the following is a specification. I My invention has to do with a block or brick peculiarly adapted for use in paving and other'places-where the block is subjected 1 to-heavy-traffic and vibration and is or is not 7 mixture of asphalt, i dust and sand. .35 i

Jone-half or three-quarters of an inch in" constantly subjected to the weather.

The purpose of my invention is to provide such a block, which will have all the advantages of and be'superior to sheet asphalt, but which utilizes natural asphaltic' rock,

rather than mixturesoif asphalt or tar, sand,

dust and rock, thereby utilizing material available in this country and reducing the 4 cost of the product, and which can be made There are generally'speaking several types of paving in which asphalt is used, sheet -asphalt, asphaltic concrete, and 'asphalt blocks.-- i

In sheet asphalt, there is employed a mixture is accomplishedin a plantand is dumped, spread-and stamped or-r'olled on the street.- 1 This type of paving hasthe disadvantage of requiring that the material be transported to the place ofin'stallation and that many different labor operations must there be performed. My blocks are made in the factory. Labor cost is cheaper and more uniform, high grade product can be pr'oducedu The number of operations on the job and the labor of laying is much less.

In asphaltic concrete (fine aggregate), the same'materials as are used in the making of sheet asphalt are employed with the addition of rock of a variety of sizes up to greatest diameter, and the paving is prepared and laid on the job as in the case, of

' sheet asphalt with similar disadvantages;

In asphaltic concrete (coarse aggre ate), the same ingredients are used as 1n asp ialtic The to variations in compressing.

Application filed August 27, 1924. Serial No. 734,544.

concrete with the addition of rock up to one inch or one and one-half inches in size, and the paving is prepared and laid on the job similar to sheet asphalt. Actual experience, especially under heavy trafiic conditions has demonstrated that sheet asphalt makes the best and most lasting paving. The paving with the larger sizes of rock deteriorates more rapidly and develops cracks and holes more extensively.

There is another type of asphalt pavement (patented), which may be the same as sheet asphalt and asphaltic concrete, with the addition of copper sulphate to the melted asphalt. I

Still another type utilizes earth, clay ornatural sandy soils mixed with asphalt,

Rock asphalt, such as the Kentucky rock asphalt and Uvalde rock asphalt are ground and used in constructing pavements by being spread and rolled.

Asphalt blocks-have been prepared and. .used, but so far as I have been able to ascertain, none have been employed, having thes'ame ingredients and qualities, or the "same method of preparation as mine.

The greatest fault with all asphalt pavements is due to lack of uniformity. Lack of uniformity is due to compounding batches of asphalt, due to variations of mineral aggregate, due'to' variations in weighingydue to variations in temperatures, due to variations in mixing, duet-o variations in spreading, due to variations in thickness and due With mixtures containing large particles of stone, uniformity becomes more diflicult and the strain upon the 'cementitious material, asphalt, isgreater. Such mixtures are more apt to disintegrate on account of hammering action on the pavement 'fracturparticles and forming pits,

'ferred to, it is not possible .to get the uniformity of compounding asphalts, blending mineral aggregate, weighing, temperature, mixing, spreadlng, thickness and compressing, that I will be able to secure in my I find that a block of maximum efliciency for the heavy duty of paving must have certain qualities that are secured only by careful selection and preparation of the ingredients. Such a block must have great durability and therefore must have to a high degree, homogeneity or uniformity of mass, uniformity of density, impermcability to water, malleability to resist wear and abrasion and certain elasticity. These qualities- I have attained by the selection of materials and method of preparation of my block.

My process includes as oneof its first steps, the examination of the rock and of the asphalt contained in the asphalt rock as found. p

I have found that certain rock in asphaltic rock deposits is capable of producing superior block to those produced by other deposits.

The asphalt contained in the 'rockdeposits is analyzed to determine its suitability for the purpose of making blocks for paving' or other uses, and if'found deficient in certain essential qualities, these qualities are supplied by proper heating or addition of required rectifying materials, such as asphalt, dust, sand or oils or by the taking away 'of certain detrimental elements or 4 .compounds.

In the block, I have made, I found that v the asphalt contained in the rock deposit was of a suitable consistency and quality if rectified by a certain grade of asphalt in small quantities. This was done by grinding the rock, heating and mixing while hot with the required amount of hot asphalt, then weighedand pressed into shape with a hydraulic press. I have in thismanner secured absolute density. Blocks that have been kept under water for three years have shown no signs of absorbing any water or of deterioration.

I have also examined other asphalt ro'ck deposits, which in order to utilize successfully will be given a heat treatment, which it is possible to predetermine so as to produce a satisfactory block.

I have also produced block from another matter or rock produces a block of a quality V less desirable for paving purposes, but more i desirable for flooring.

Thus it can. be seen that my process of utilizing asphalt rock for manufacturing pavements or blocks'is different than any process heretofore utilized, and that one of the important steps in my process is the analyzation of the rock deposit and predetermining the steps necessary for producing a satisfactory quality for the purpose to which the block will be used.

In all cases, where asphalt rock has here more uniformity in blending, thereby also resulting in a more uniform product.

The matter of compressing into blocks under great pressure secures a density which it i is impossible to secure by rolling or tamping.

Asphalt manufactured and used for paving purposes have not been made of mineral aggregates under one-fourth of an inch and excluding the larger particles, nor have they been made of asphaltic rock pulverized and rectified as necessary.

I select natural asphaltic rock having an asphaltic content of from four to twelve pcrcentum.

The rock is ground, so that as used, subblocks as heretofore and now stantially all of it should pass through a ten mesh screen and approximately ten percentum or-more should be of a size to pass through a two hundred mesh screen. The mixture of ground rock is then heated to from two hundredto three hund ed and fifty degrees Fahrenheit for meliinj'" the asphalt and thoroughly diii'us' through the mass. The ground r preferably stirred or agitated din-i heating to insure thorough mixing particles to secure uniform density and homogeneity and proper diffusion of the asphalt. If it is desired to add more asphalt to the mixture, this is donewhile the mixture is hot. If it is desired to reduce the asphalt content, hot sand or mineral aggregate. is added to the mixture. .The mixture is preferably weighed before being pressed, so that all blocks are of the same size and density.

While the mixture is hot, it is placed in moulds and subjected to great pressure, as for example 7500 pounds to the square inch.

The product may be stored-0r shipped as soon as it has cooled-"in By thus properly selecting the materials and processing the rock, there is secured a proper asphaltic content, mineral mixture give slightly until the joints hetweenthe I claim as my 'invention:-

blocks can scarcely-be distinguished;

1. An asphalt-block comprising asphaltic rock with approximately four to twelve percentum' asphaltic 'content, ofiapproxil niately fineness to passa ten lnes'h sc'reen with approximately ten peroentnm'fiof a fineness to pass a two hundredtmesh screen,

mixed, heated and moulded while hot up (101' rea Pressure.

2.The process ,of making asphalt blocks comprising the grinding of asphaltio rock of the as'phaltic content. of four to twelve percentum, till substantially all will -pass aten mesh screen and substantially one tenth will pass a two hundred mesh screen,

mixing and heating the ground rock tpatemperature of over-twohundred and fifty degrees Fahrenheit and moulding the mixture under pressure of approximately sev-- enty five hundred pounds to the square inch to the, ii nished form. 1 p

The' process of making asphalt blocks comprising the grinding of asplfaltic rock of. the asphaltic content offour to twelve percentuni tillsubstantially all will pass a ten mesh screen and substantially one tenth will. pass a two hundred meshscreen,

mixing and heating the ground rock t0 a temperature of over two hundred and fifty degrees-Fahrenheit and moulding the mixture'unjder great pressure. Des alvloines, Iowa, August 1, 1924.

. "Mo neon LAWRENCE PATZIG, 

